Manifold for gas engines



J. G. SNYDER. MANIFOLD FOR GAS ENGINES.

l El) JULY 19,1920.

Patented Apr. 25, 1922.

r umran STATES Par MANIFOLD FOR GAS ENGINES.

.To all whom it may concern:

Be it 'known that I, JOHN G. SNYDER, a,

and useful Improvements in Manifolds for Gas Engines, of which the following is a full and complete specification.

It is customary by means of a carbureting device to produce a gaseous, or mixed aseous and liquid fuel in a stream to be elivered to the several explosion chambers of a gas engine. Dependent upon the speed.

of the engine and the existing temperature great variation is frequently found in the quality of fuel which'is delivered to the respective cylinders. It is also obvious that the difference in the length of travel to the various cylinders further effects the uniformity of the fuel stream. To properly,

deliver to each of the cylinders in a gas engine a stream of gaseous fuel of uniform character is an importantfactor in the maintenance of good gas engine operation. De-- pendent upon.,;var1ous temperature changes in the air passing the carburetor and the surrounding machine parts there is a corresponding variation in the degree to which the liquid fuel is vaporized. It is frequently found that the fuel is entrained in a current of air and may even arrive in the explo sion cylinders in the form of small globules. Under these circumstances there is a consequent loss in motive. force.

Itis an objectof my invention to blend the vaporized fuel thoroughly with the air stream as it passes into the various cylinders of the engine and thus promote the operation of the latter.

It is a further object of my invention to insure uniformity in the delivery of the gaseous mixture to the, cylinders avoiding all possibility of feeding a lean mixture to one cylinder and a rich mixture to another.

- It is also a further object of my invention to insure a perfect vaporization of such portions of the fuel as may pass the carburetor Without volatilization. As will be evident from the description this is accomplished both by mechanical means and through heat transference. I

Other objects of my invention will be evident from the following description taken in conjunction with the drawings in which Fig. 1 shows a longitudnal cross section for a typical four-cycle engine.

Specification of Letters Patent. Patented A 25', 1922. Application filed July 19,

1920. Serial No. 39%.,448.

of a manifold embodying one form of my invention and taken-along the line 1-1 of Fig. 2. l

. Fig. 2 is a transverse cross-section through 2-2'of Fig. 1.

As illustrated in the drawings one form of my invention consists in the casting 3 which provides suitable chambers and passage-ways for exhaust, intake,and'"mixing of the fuel.

Ports 4 pass through one side of the casting and connect with the\exhaust ports of the respective cylinder heads, in the present instance the casting being shown as adapted The ports 4 deliver the exhaust gases to the channels 5 which have their prolongation in the member 6 internally screw-threaded for connection with the customary exhaust tubing. In

line with the centres of the ports 4 are the inlet ports 7 which are branched, not shown, to connect with the inlet ports or valves of the gas engine. It is to be understood that each port 7 serves two cylinders The ports 7 areconnected by means of the passage ways 8 to a chamber 9extending the full exhaust or lower side thereof to provide a small partition which is advantageous as will hereinafter appear. An inlet 13 is disposed above the center of the recess 13 and connects the mid-portion of the chamber 9 with the carburetor of the engine. The top wall 14 of the vaporizing recess is slotted as at 15 throughout-its entire length and this slot at its ends becomes a corresponding groove '16 in the side walls 17 and 18 of the duct. :This slot connects the vaporizing recess 13 with the longitudinal chamber 9.-

Disposed throughout the length of the chamber 9, co-axi-al therewith, and substantially in contact with its inner wall is a mixing device 19. This mixing device 0011- 1 sists of a blade twisted" into a helicoidal form 'for the greater part of its length. This.

of the member 19.

. through the slot 14 and into the recess 13.

helicoidal form consists of two helices 20 and 21 merging at the centre as at 22 and having opposite pitches extending the complete width of the chamber 9 and aggregating the length of the slot 1 1 of the vaporizing recess. The helices, at this central meeting point, merge and may be said to have a neutral pitch since they serve to receive the gas and unvolatilized fuel coming from the inlet 13 and divide the stream equally part going in each direction. Beyond the helices 20 and 21 are the rod ends 23-and 24c.

A thin metal bar 25 is provided the length of the slot 14 and the groove 18, and of a width sufficient to occupy the width of the groove. This bar is cut away on one side for a length equal to that of the slot 1 1 and a blade 26' is set up from the corresponding side at an inclination to the radius of the adjacent helix. This blade 26 intersects the helices in a line parallel to the axis of the latter. The helices may be cut away to permit the use of a blade of continuous edge or conversely the blade may be cut away at reg ular intervals to permit the passage of a continuous helix. 1

In either event the blade and the mixing member 19 are assembled I rior to installing in the manifold casting. he pipe plugs 10 and 11 are of suflicient diameter to permit the insertion of the assembled members 19 and 25, the latter to seat themselves in the chamber 9 being properly spaced from the ends of the pipe plugs 10 and 11 by the rod ends 23 and 24. The helices are in substantial contact with the inner walls of the chamber 9 and the bar 25 rests in the groove 16.

In the form as shown in the drawing, the stream entering through the inlet 13' meets the divergent helices andis divided, forming two streams travelling toward opposite ends As these streams follow their spiral courses, the centrifugal effect is such as .to cause the liquid fuel particles to approach the sides of the chamber 9. As the particles reach the lower point of travel and the inwardly extending blade 26, they are caught and deflected by the latter downward This recess is heated by the passage of the exhaust gases in contact with the lower wall 12 and the entering particles of fuel are therefore uickly vaporized. As the fuel vap'orizes, 1t expands and travels upward through the slot 14, mingling with the .fuel streams as they pass through the chamber 9.

From the above description it will be evident that a fuel stream from a carburetor will be effected in the following manner. As

7 the stream enters through inlet 13' into the chamber 9, it' is divided into two equal streams toward the opposite ports 7. The

spiral path carries the liquid fuel particles centrifugally and thus serves to strain or separate the stream of all but vaporized comyaporized and homogenized.

ponents. During this step it will be apparent that the fuel is kept out of contact with heated surfaces and its temperature remains low. The globules of fuel, segregated by centrifugal force and under the influence of gravity, are intercepted by the blade 26 and pass down beyond the bar 25, into the recess 13. Due to the proximity .of the latter recess to the exhaust gas passage ways, the liquid fuel is caught in the recess and vaporized.

There results a consequent expansion of the fuel as vapor, and the increased Volume produces a current upward through the slot 14 in contact with the descending liquid particles. The vaporized fuel now blends with the fuel stream passing the helices and is thoroughly mixed. The flow upward through the slot 14 is at an increased velocity due to the volatilization and expansion of the fuel under heat in the recess 13 and this upward flow impinges against the blade 26 with considerable violence. This is an added factor in promoting the mixing of the material in the chamber 9.

It is remarked that the blade 26 when in tercepting the entrained globules will'also deflect a small quantity of the gaseous stream downward into the recess. This-quantity of gas has a. sweeping or scavenging effect in the recess and aids in the return to the chamber 9, of the vaporized fuel. It will be apparent from Fig. 1 that the blade 26 is subdivided into a number of parts by its intersections with the helices 20 and 21. By tracing the current flow .from the inlet 13 it will be fluence of the blade. ;T here is thus produced what has been above termed a scavenging-effect .whereby eddy-currents flow into the ends of the chamber 13 and outward through its central area. It is further noteworthy that the fuel stream from the carburetor to the inlet ports 7 is not subjected as an entirety to heating influence, but on the contrary a separation is effected of the gaseous portionfrom the heavier and unvaporized particles and the latter only are heated. In thismanner the volumetric efficiency of the fuel stream is maintained unimpaired.

During the passage through the slot 14 and the mixer the fuel mixture is thoroughly In passing through the helices the charge is kept uniform in the two directions which it takes through the mixer. It will be evident that the fuel charge is therefore delivered to the ports 7 in uniform streams and that the helices serve the further object of preventing back pressure or eddy currents.

The particular embodiment of n)" invention shown, is of course, Susceptible of considerable variation without departing 'from' the spirit of my invention, and it is to be understood that many changes may be made by those skilled" in the art, within the scope of. the invention as defined in the appended claims. I

I claim:

1. A manifold having an inlet duct, one or more passageways adapted to convey fuel to the inlet valves of a gas engine, a mixer interposed between said duct-and a passageway, said mixer including means to separate out unvaporized fuel intercepting means for said unvaporized fuel, and a vaporizing recess for receiving said unvaporized fuel.

2. A manifold having an inlet duct, one or more passageways adapted to convey fuel to the inlet valves of a gas-engine,'a helicoidal-v mixer interposed between said 'duct and a passageway, and intercepting means contiguous to and projecting within the periphery of said mixer.

3. A manifold havin an inlet duct, one or more passageways a apted to convey the fuel to the inlet valves of a gas engine, a mixer interposed between said duct and a passageway, and a blade within the passageway mclined to the fuel stream flowing throu h the mixer.

4. manifold having an inlet duct, a plurality of passageways adapted to convey fuel to the inlet valves of a gas engine, mixers, one of said mixers being interposed between said duct and each passageway, said mixers segregating unvaporized fuel, intercepting means for said unvaporized fuel, said manifold having a vaporing'recess for receiving-said unvaporized fuel and returning it to the passageways in the form of vapor.

5. A manifold having an inlet duct, a passageway adaptedto convey fuel to the inlet valves of a gas engine, means interposed between said duct and the passageway for mixing air and gaseous fuel and for segre: gating unvaporized fuel, intercepting means for said unvaporized fuel, said manifold having a vaporizing recess to receive the intercepted fuel.

6. A manifold having an inlet duct, a plurality of passageways adapted to convey fuel to the inlet valves of a gas engine, helicoidal mixers, one of said mixers being interposed between said duct and each passageway, and intercepting means projecting within the periphery of the mixers.

7. A manifold having a plurality of passageways to the inlet valves of a gas engine,

including a mixing chamber connecting said passageways, said manifold-having 'a recess underlying the said chamber connecting therewith and in close relationship to the exhaust passages of the gas engine.

8. A manifold having a plurality of passageways to the inletv valves of a gas engine, including a mixing chamber connecting said passageways, said manifold having a recess underlying the said chamber connecting therewith and in close relationship to the exdevice for a man1fold,'com- 

